[Preparative isolation and purification of five non-volatile compounds from Fructus caryophylli and Flos caryophylli by high-speed counter-current chromatography]

Abstract

A high-speed counter-current chromatographic (HSCCC) method was successfully developed for the isolation of three non-volatile compounds from Fructus Caryophylli and two chromone compounds from Flos Caryophylli. The optimum separation solution systems included system A (n-hexane-ethyl acetate-methanol-water (5:8:6: 13, v/v/v/v) and system B (n-hexane-ethyl acetate-methanol-water (5: 8: 9: 10, v/v/v/v). The upper phase of the system A was used as the stationary phase, and the lower phases of the systems A and B as the mobile phases were operated at a flow of 1.2 mL/min, while the apparatus rotated at 880 r/min. The 12.3 mg of ellagic acid, 9.6 mg of rhamnetin, 17.2 mg of quercetin were successfully purified from 70 mg of the crude extract of Fructus Caryophylli by a two-step separation. In the same way, 10.2 mg of 5,7-dimethoxy-2-methylchromone, 8.6 mg of 5,7-dimethoxy-2,6-dimethyl-chromone were purified from 50 mg of the crude extract of Flos Caryophylli. The purities of the compounds were all over 96% as determined by high performance liquid chromatography (HPLC). The five compounds were indentified by mass spectrometry (MS), 1H-nuclear magnetic resonance (NMR) and 13C-NMR. The results indicate that HSCCC is a powerful technique for the purification of non-volatile compounds from different parts of Eugenia caryophylla Thunb.